Differential controls of water input on litter decomposition and nitrogen dynamics in the patagonian steppe

Laura Yahdjian, Osvaldo Sala, Amy T. Austin

Research output: Contribution to journalArticle

99 Citations (Scopus)

Abstract

Studies of the effects of precipitation on litter decomposition and nitrogen mineralization in arid and semiarid environments have demonstrated contradictory results. We conducted a manipulative experiment with rainout shelters in the semi-arid Patagonian steppe, aimed at assessing the direct effects of water availability on litter decomposition and net nitrogen mineralization while isolating the indirect effects. We created four levels of precipitation input: control and three levels (30, 55 and 80%) of precipitation interception and we examined litter decomposition and nutrient release of a dominant grass species, Stipa speciosa, inorganic soil nitrogen, and in situ net nitrogen mineralization over two consecutive years. Litter decomposition rates (k, year-1) varied significantly (P < 0.001) among precipitation interception treatments and were positively correlated with incoming annual precipitation (APPT, mm/year) (k = 0.0007 x APPT + 0.137). In contrast, net N mineralization was not correlated with incoming precipitation. Soil NO 3 - significantly decreased with increasing precipitation input, whereas soil NH4 + concentration did not differ among precipitation interception treatments. Controls of water input on litter decomposition appear to be different from controls on N mineralization in the semiarid Patagonian steppe. We suggest that although water availability affects both the mineralization of C and N, it differentially affects the movement and fate of the inorganic products. A consequence of the accumulation of inorganic N during dry episodes is that periods of maximum water and soil nutrient availability may occur at different times. This asynchrony in the availability of N and water in the soil may explain the observed lags in the response of primary production to increases in water availability.

Original languageEnglish (US)
Pages (from-to)128-141
Number of pages14
JournalEcosystems
Volume9
Issue number1
DOIs
StatePublished - Feb 2006
Externally publishedYes

Fingerprint

steppes
steppe
mineralization
litter
Nitrogen
decomposition
Decomposition
Availability
degradation
Water
nitrogen
Soils
interception
water availability
water
Nutrients
soil
Stipa
soil nitrogen
nutrient availability

Keywords

  • Arid ecosystems
  • Decomposition
  • Net N mineralization
  • Patagonian steppe (Argentina)
  • Phosphorus and nitrogen release
  • Rainfall interception
  • Rainout shelter
  • Soil NO and NH
  • Stipa speciosa
  • Water manipulations

ASJC Scopus subject areas

  • Ecology

Cite this

Differential controls of water input on litter decomposition and nitrogen dynamics in the patagonian steppe. / Yahdjian, Laura; Sala, Osvaldo; Austin, Amy T.

In: Ecosystems, Vol. 9, No. 1, 02.2006, p. 128-141.

Research output: Contribution to journalArticle

@article{3cf886b179cd4ada91391a5c423a7be6,
title = "Differential controls of water input on litter decomposition and nitrogen dynamics in the patagonian steppe",
abstract = "Studies of the effects of precipitation on litter decomposition and nitrogen mineralization in arid and semiarid environments have demonstrated contradictory results. We conducted a manipulative experiment with rainout shelters in the semi-arid Patagonian steppe, aimed at assessing the direct effects of water availability on litter decomposition and net nitrogen mineralization while isolating the indirect effects. We created four levels of precipitation input: control and three levels (30, 55 and 80{\%}) of precipitation interception and we examined litter decomposition and nutrient release of a dominant grass species, Stipa speciosa, inorganic soil nitrogen, and in situ net nitrogen mineralization over two consecutive years. Litter decomposition rates (k, year-1) varied significantly (P < 0.001) among precipitation interception treatments and were positively correlated with incoming annual precipitation (APPT, mm/year) (k = 0.0007 x APPT + 0.137). In contrast, net N mineralization was not correlated with incoming precipitation. Soil NO 3 - significantly decreased with increasing precipitation input, whereas soil NH4 + concentration did not differ among precipitation interception treatments. Controls of water input on litter decomposition appear to be different from controls on N mineralization in the semiarid Patagonian steppe. We suggest that although water availability affects both the mineralization of C and N, it differentially affects the movement and fate of the inorganic products. A consequence of the accumulation of inorganic N during dry episodes is that periods of maximum water and soil nutrient availability may occur at different times. This asynchrony in the availability of N and water in the soil may explain the observed lags in the response of primary production to increases in water availability.",
keywords = "Arid ecosystems, Decomposition, Net N mineralization, Patagonian steppe (Argentina), Phosphorus and nitrogen release, Rainfall interception, Rainout shelter, Soil NO and NH, Stipa speciosa, Water manipulations",
author = "Laura Yahdjian and Osvaldo Sala and Austin, {Amy T.}",
year = "2006",
month = "2",
doi = "10.1007/s10021-004-0118-7",
language = "English (US)",
volume = "9",
pages = "128--141",
journal = "Ecosystems",
issn = "1432-9840",
publisher = "Springer New York",
number = "1",

}

TY - JOUR

T1 - Differential controls of water input on litter decomposition and nitrogen dynamics in the patagonian steppe

AU - Yahdjian, Laura

AU - Sala, Osvaldo

AU - Austin, Amy T.

PY - 2006/2

Y1 - 2006/2

N2 - Studies of the effects of precipitation on litter decomposition and nitrogen mineralization in arid and semiarid environments have demonstrated contradictory results. We conducted a manipulative experiment with rainout shelters in the semi-arid Patagonian steppe, aimed at assessing the direct effects of water availability on litter decomposition and net nitrogen mineralization while isolating the indirect effects. We created four levels of precipitation input: control and three levels (30, 55 and 80%) of precipitation interception and we examined litter decomposition and nutrient release of a dominant grass species, Stipa speciosa, inorganic soil nitrogen, and in situ net nitrogen mineralization over two consecutive years. Litter decomposition rates (k, year-1) varied significantly (P < 0.001) among precipitation interception treatments and were positively correlated with incoming annual precipitation (APPT, mm/year) (k = 0.0007 x APPT + 0.137). In contrast, net N mineralization was not correlated with incoming precipitation. Soil NO 3 - significantly decreased with increasing precipitation input, whereas soil NH4 + concentration did not differ among precipitation interception treatments. Controls of water input on litter decomposition appear to be different from controls on N mineralization in the semiarid Patagonian steppe. We suggest that although water availability affects both the mineralization of C and N, it differentially affects the movement and fate of the inorganic products. A consequence of the accumulation of inorganic N during dry episodes is that periods of maximum water and soil nutrient availability may occur at different times. This asynchrony in the availability of N and water in the soil may explain the observed lags in the response of primary production to increases in water availability.

AB - Studies of the effects of precipitation on litter decomposition and nitrogen mineralization in arid and semiarid environments have demonstrated contradictory results. We conducted a manipulative experiment with rainout shelters in the semi-arid Patagonian steppe, aimed at assessing the direct effects of water availability on litter decomposition and net nitrogen mineralization while isolating the indirect effects. We created four levels of precipitation input: control and three levels (30, 55 and 80%) of precipitation interception and we examined litter decomposition and nutrient release of a dominant grass species, Stipa speciosa, inorganic soil nitrogen, and in situ net nitrogen mineralization over two consecutive years. Litter decomposition rates (k, year-1) varied significantly (P < 0.001) among precipitation interception treatments and were positively correlated with incoming annual precipitation (APPT, mm/year) (k = 0.0007 x APPT + 0.137). In contrast, net N mineralization was not correlated with incoming precipitation. Soil NO 3 - significantly decreased with increasing precipitation input, whereas soil NH4 + concentration did not differ among precipitation interception treatments. Controls of water input on litter decomposition appear to be different from controls on N mineralization in the semiarid Patagonian steppe. We suggest that although water availability affects both the mineralization of C and N, it differentially affects the movement and fate of the inorganic products. A consequence of the accumulation of inorganic N during dry episodes is that periods of maximum water and soil nutrient availability may occur at different times. This asynchrony in the availability of N and water in the soil may explain the observed lags in the response of primary production to increases in water availability.

KW - Arid ecosystems

KW - Decomposition

KW - Net N mineralization

KW - Patagonian steppe (Argentina)

KW - Phosphorus and nitrogen release

KW - Rainfall interception

KW - Rainout shelter

KW - Soil NO and NH

KW - Stipa speciosa

KW - Water manipulations

UR - http://www.scopus.com/inward/record.url?scp=33645810140&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33645810140&partnerID=8YFLogxK

U2 - 10.1007/s10021-004-0118-7

DO - 10.1007/s10021-004-0118-7

M3 - Article

VL - 9

SP - 128

EP - 141

JO - Ecosystems

JF - Ecosystems

SN - 1432-9840

IS - 1

ER -